Because depression is a major source of the global burden of illness-related disability, developing effective strategies for reducing its incidence is an important public health priority, especially in low-income countries, where resources for treating depression are scarce. We describe in this report an intervention development project, funded by the US National Institute of Mental Health, to address “indicated” prevention of depression in older adults attending rural and urban primary care clinics in Goa, India. Specifically, participants in the “DIL” (“Depression in Later Life”) trial were older adults living with mild, subsyndromal symptoms of depression and anxiety and thus at substantial risk for transitioning to fully syndromal major depression and anxiety disorders. Building upon the MANAS treatment trial (“Promoting Mental Health”) led by Patel et al. in the same locale, we present here lessons learned in the development and implementation of a protocol utilizing lay health counsellors (LHCs) who deliver a multi-component depression prevention intervention organized conceptually around Problem Solving Therapy for Primary Care (PST), with additional components addressing brief behavioural treatment of sleep disturbances such as insomnia, meeting basic social casework needs, and education in self-management of prevalent comorbid chronic diseases, such as diabetes mellitus. To our knowledge, DIL is the first randomized clinical trial addressing the prevention of depressive disorders ever conducted in a low- or middle-income country.